Condensate disposal means for selfcontained air conditioners



June 21, 1960 E, M. wuEsTHoFF 2,941,382

CONDENSATE DISPOSAL MEANS FOR saw-comma AIR CONDITIONERS Filed Jan. 20. 1959 FIGZ) INVENTOR EDWARD M. WUESTHOFF ATTORNEY CONDENSATE DISPOSAL MEANS FOR SELF- CONTAINED AIR CONDITIONERS Edward M. Wuesthotf, Agawam, Mass, assignor to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed Jan. 20, 1959, Ser. No; 787,851

3 Claims. (Cl. 62-280) This invention relates to air conditioning apparatus and more particularly to condensate disposal arrangements for self-contained room air conditioners.

In attempting to obtain higher cooling capacities from compact room air conditioners, it has been found desirable to employ higher speed fans, or blowers, in order to propel air through the comparatively restricted air passages resulting from the small overall'size of the conditioner. It has also become desirable to utilize multibank, finned tube heat exchangers in order to obtain sufficient heat transfer area from heat exchangers of small height and width. A multi-bank heat exchanger is one in which there are several rows of refrigerant tubes spaced through the depth of the heat exchanger. Such heat exchangers otter more resistance to air flow than do single bank heat exchangers.

The above factors have created problems, particularly with respect to the disposal of condensate in the outside air section of the conditioner. As is well understood,

it is common practice to dispose of condensate removed' from the room air by discharging it onto the outside heat exchanger, or condenser, whereby it is evaporated into the outside air. A slinger ring operating in conjunction with the condenser fan and a condensate sump is generally employed to lift the condensate into the condenser air stream. In present-day, compact units a relatively high speed fan is disposed in closely spaced face-to-face relation to a multi-bank condenser and both' are at least partially enclosed by an air directing casing of shroud which also covers a portion of the condensate sump. offered by the condenser causes the interior of the casing to operate under positive static air pressure. The rapidly turning fan also produces a rapidly rotating body of air within the casing. These two conditions adversely afiect the operation of the condensate disposal system in that they tend to exclude condensate from the region of the sump in which the slinger ring operates. In other words, that portion of the sump operates dry, sothat the slinger ring is unable to lift condensate into the condenser air stream, with the result that condensate overflows. the sump and drips from other regions of the air conditioner.

It is the principal object of this invention to improve the condensate disposal system of compact, high capacity air conditioners. A more particular object is the provision of an efiicient condensate disposal system for air conditioners which are subject to the adverse operating conditions described above.

In accordance with this invention, a condensate lifting strip is disposed in the sump in a region beneath the condenser fan. This upwardly extending strip is preferablyarranged parallel to the axis about which the fan rotates and has an upper edge disposed closely adjacent the outer ends of the fan blades. An upright edge of the In such arrangements the resistance to air flow.

- permit condensate to enter the region of the sump which 2,941,382 Patented June 21, 1960 strip is preferably disposed closely adjacent the slinger ring associated with the fan. The rotating massof air in the condenser casing impinging against one face of this strip and flowing around the edges of the strip creates a region of negative pressure, or suction, on the opposite face of the strip, which induces a flow of condensate into that region of the sump and causes the condensate to rise up the opposite face of the strip. On leaving the edges of the strip, the condensate is picked up by the blades of the fan and the slinger ring and is lifted or propelledi into the condenser air stream. 1

This strip preferably extends beneath the lower edge Fig. 2 is an enlarged, fragmentary sectional view" through the outside'air section of the air conditioner and is taken as indicated by line II--II in Fig. 1; and

Fig. 3 is an enlarged fragmentary view of the sump region of the air conditioner shown in Fig. 1.

The air conditioner comprises a casing 11 having a partition 12 therein dividing the conditioner into an in door air section 13 and an outdoor air section 14. Room air enters the conditioner through the lower portion of the front wall 15 thereof and is propelled by a motor driven blower 16 through a cooling unit 17 which cools and dehumidifies the air before it is returned to the room. The cooling unit 17 is the evaporator of a compression refrigeration system which also includes a compressor (not shown) and a condenser which is divided into upper and lower sections 18 and 19, respectively. Heat absorbed from room air is dissipated to outside air by the condenser sections 18 and 19. Outside air is circulated over the condenser sections by a motor driven propeller fan 20 which is disposed in face-to-face relationship to, and closely adjacent the lower condenser section 19, and is rotatable on a-horizontal axis. The direction of air flowis indicated by the arrows in the drawing. Air enters the outside face of the conditioner, flows through upper condenser section 13, and is confined to flow through fan 20 and condense-r section 19 by an open bottom casing or shroud 21, which at least partially surrounds condenser section 19 and fan 20 and has an air inlet opening 22 through which air is moved by the fan.

The lower edge of condenser section 19, the bottom edge of the casing 21 and a lower portion of a slinger ring 23 carried by the fan 20 are disposed in a sump 24 resting on the bottom of the casing 11 and adapted to contain a body of condensate 25. Condensate, that is,

moisture condensed from the room air by cooling unit 17,

The bottom edge of condenser section 19 and at least some portions of the lower edge of the casing 21 are preferably spaced from the bottom of the sump 24 to is covered by the casing 21, so that it may be contacted by the slinger ring 23. Regardless of this provision for and the separate sump condensate to enter the enclosed portion of the sump 24, it has been observed that there is a tendency for this region of the sump to run dry, that is, free of condensate, with the result that condensate tends to overflow from other regions of the sump 24. This has been shown to be due to at least two factors. In the first place, the condenser section 19 is formed of a number of rows or banks of refrigerant tubes 27 which have a plurality of closely spaced vertical fins 28 arranged transversely of the tubes. This structure offers considerable resistance to flow of air therethrough and causes static air pressure to be built up within the casing 21, which tends to exclude condensate from the covered region of the sump 24. Also, the fan 20, in rotating at a relatively high speed (of the'order of 1100 rpm. or more) imparts a rotating motion to the bodyof air within the casing 21. This moving mass of air also tends to blow or move the condensate 25 away from the region of the sump 24 in which the slinger ring 23 operates.

In accordance with this invention, means are provided for causing condensate to flow into the region of the sump which is covered by the casing, and, particularly for causing'cond'ensate to flow onto the slinger ring 23 and the blades of the fan 20. This means includes a strip 29, preferably made of thin sheet metal, which is disposed in the sump 24 and extends upwardly from the bottom of the sump. The broad faces of the strip 29 are disposed parallel to the axis about which the fan 20 rorates, so that one face 30 thereof is upstream and the other face 31 is downstream with respect to the rotating mass of air which surrounds the fan 20.

The strip 29 has one end portion 32 thereof extending beneath the fan 29, that is, into an area which is coextensive with the axial extent of the fan 20. The upper edge of the strip, identified as 33, terminates closely adjacent the outer ends of the blades of the fan 20. An upright edge, identified at 34, of this portion of the strip 29 is located closely adjacent the slinger ring 23. It has also been discovered that operation of the strip 29 is improved if a slot is provided in an upper portion thereof to provide another upright edge 35 between the fan 20 and the condenser section 19.

The strip 29 has another portion 36 thereof extending beneath the lower edge of the condenser section 19. This portion of the strip may be provided with a plurality of notches 37 in its upper edge which are adapted to receive tubes 27 of the condenser section 19. Disposing strip 29 between two adjacent fins 28 of the condenser section (see Fig. 2), with interengagetnent of condenser tubes 27 and notches 37 preventing longitudinal movementof the strip, provides a convenient arrangement for supporting and positioning the strip 29 on the bottom of the sump 24.

In operation, air moved by the fan 20 and impinging against the upstream face 30 of the strip 29 flows around the edges 33, 34' and 35 of the strip and creates a negative pressure or suction on the downstream face 31 of the strip. This negative pressure induces condensate to flow beneath the condenser section B and along the downstream face 31 of the strip to that portion 32 of the strip which is disposed beneath the fan 20. This condensate flows up the downstream face '31 of the strip and leaves the edges 33 and 34 of the strip-in the form of a'spray of droplets which are picked up by the'blades of the fan 2! and the slinger ring 23 and thrown into the stream of air being propelled through condenser section 19. Thus, although the area or region of the sump adjacent the lowermost portion of the slinger ring 23 may not contain condensate 25, there is provided a means for conveying condensate onto the slinger ring and the blades 29 to insure its being dissipated into the condenser air stream.

Experimentation has shown the best location of the strip 2% to be approximately that shownin Fig. 2 oftthe drawing, 'in which the strip is displaced from beneath the vertical centerline of the fan 20 in the direction in which the lower portion of the fan moves.

From the foregoing it will be apparent that this invention provides improved means for directing condensate into a covered and pressurized region of a sump and for insuring that the condensate is lifted into the condenser air stream, either by a slinger ring or a fan propelling air through the condenser. The invention thus enables air conditioners to employ compact outside air sections which, without the benefits of the invention, would not be capable of effectively and efficiently disposing of condensate removed from the room air.

While the invention has been shown in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

What is claimed i 7 1. In an air conditioner, a condensate pan, a finnedtube condenser having the bottom edge thereof disposed in said condensate pan and spaced from the bottom of said pan, a propeller fan rotatable on a horizontal axis and disposed in closely spaced face-to-face relation to said condenser, an open bottom casing disposed in said pan and at least partially enclosing said fan and said condenser, said fan when rotating creating positive air pressure in said casing tending to exclude condensate fromthat portion of the pan which is covered by said casing, and means for directing condensate onto the blades of said fan for delivery to said condenser, said means comprising a strip extending upwardly from the bottom of said pan in a plane parallel to the axis of said fan, said strip having at least one port-ion thereof disposed beneath said condenser and another portion thereof extending beneath said fan, the upper edge of said strip terminating closely adjacent the outer ends of the blades of said fan.

entrance of condensate into that portion of the pan which is covered by said casing, a slinger ring on said fan having the lower portion thereof in said pan, and means for directing condensate onto said slinger ring and the blades of said fan for delivery to said condenser,

saidmeans comprising an upright, horizontally elongated strip projecting upwardly from the bottom of said pan between two adjacent fins of said condenser, said striphaving at least a portion thereof extending beneath said fan and having its upper edge terminating closely ad acent the outer ends of the blades of said fan and having an upwardly extending edge disposed adjacent said slingerring. 7

3. In an air conditioner, a condensate pan, a finnedtube condenser having the bottom edge thereof disposed in said condensate pan, a propeller fan rotatable on a horizontalaxis and disposed in closely spaced faceto-face relation to said condenser, an open bottom casing disposed in said pan and at least partially enclosing said fan and said condenser, said fan when rotating creating positive air pressure in said casing tending to exclude the entrance of condensate into that portion of the pan which is covered by said casing, a slinger ring on said fan having the lower portion thereof in said pan, and means for directing condensate onto said slinger ring and the blades of said fan for delivery to said condenser, said means comprising an upright, horizontally elongated strip projecting upwardly from the bottom ofsaid pan between two adjacent tins of said condenser, said strip having an end portion thereof extending beneath said fan, said end portion of said strip hav 6 ing its upper edge terminating closely adjacent the outer References Cited in the file of this patent ends of the blades of said fan and having two upright edges, the first of said upright edges being located closely UNITED STATES PATENTS adjacent said slinger ring and the other of said upright 2,617,637 Moore Nov. 11, 1952 edges being provided by a slot in said strip adjacent said 6 2,793,510 Komroif May 27, 1957 condenser. 2,811,023 Lathrop Oct. 29, 1957 

